1. Field of Invention
This invention relates to high energy particle detectors and more particularly to modular high energy particle detectors which may be arranged to form large detector arrays with a uniform pattern of detector elements and which may be conveniently connected one behind the other to form stacks of detector arrays. The invention further relates to means for reading out signals generated in the separate detector elements while maximizing the total area of the array covered by detector elements.
2. Background Information
A class of detectors for the detection of charged high energy particles in the silicon calorimeter. These calorimeters are essentially passive devices in which high energy particles, normally having energies greater than one billion electron volts, impinge upon a stack of metallic plates. Each incident particle causes particles within the plates to "shower" out. The stack of plates is thick enough to contain a fully developed shower. Silicon based detector elements then detect the showering particles and provide a signal to measuring equipment which is approximately proportional to the incident particle energy. By providing an x-y array of outputs, the approximate coordinates of the incident particle as well as its energy can be determined.
A strong trend in semiconductor device technology has been toward integrating many devices and circuits on the same chip. These techniques have been applied to silicon calorimeters as discussed in Nuclear Instruments and Methods in Physics Research A238(1985) 53-60, North-Holland Amsterdam, where a 38 cm.sup.2 silicon/lead sandwich calorimeter is described, and in the same publication at A251(1986) 275-285 where a 64 cm.sup.2 silicon/tungsten sandwich calorimeter is detailed. These calorimeters utilize circular detector wafers with a checkerboard array of electrode strips to provide the coordinates of particle incidence. These devices have edge terminal strips which together with the circular configuration of the wafer would create large dead spaces if similar units were placed side by side to construct a larger array.
Another limitation of such large detectors with multiple detector cells integrated on a single semiconductor wafer is the cost of such devices. One factor in the cost of such a device is that a defect in any portion of the wafer requires replacement of the entire unit. In addition, it is a major task to change the geometry of such a detector.